Production, stability, and toxicity of small unilamellar vesicles in co-culture of in vitro produced bovine embryos

• Grant number: 23/06884-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2023
• End date: June 30, 2024
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Marcelo Fábio Gouveia Nogueira
• Grantee: Melissa Nishida Hirano
• Host Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil

Abstract

Within the biotechnology of assisted animal reproduction, in vitro production of bovine embryos is a national highlight. However, the technique induces iatrogenic changes in the embryos produced. Markedly, this is reflected in the cryotolerance of in vitro produced (IVP) embryos and in their altered lipid composition in the plasma membrane and cytoplasm. Among the most recent approaches to modulate IVP embryo lipids are synthetic lipid vesicles (i.e., liposomes). The aim of this study is to validate the formation and determine the stability and toxicity of small unilamellar vesicles (SUVs) co-cultured with IVP bovine embryos. Formations of SUVs will be tested with cholesterol (35 to 37.5 %), dipalmitoyl phosphatidylcholine (60 %) and phosphoinositides (2.5 to 5 %) in commercial embryo culture medium. Diameter will be homogenized via sonication and extrusion. The stability of the SUVs (1 nmol/L) will be analyzed at 0, 24 and 48 hours (incubation time), under embryo culture conditions and by dynamic light scattering (DLS). Finally, the toxicity will be evaluated by means of the production of blastocysts (on days 7, 8 and 9 of culture) co-cultured for 48 to 96 hours with 0 (control), 1, 2 and 3 nmol/L of SUVs. The SUVs with the best stability (within 48 hours of incubation) and, preferably, those containing 5% phosphoinositides in their composition will be chosen to toxicity test.